In so-called regenerative rotary pumps, a disc-shaped impeller with vanes around its circumference rotates at relatively high speed in a housing having a donut-shaped pumping chamber enveloping the circumference of the impeller. The pumping chamber is interrupted by a reduced cross-section portion, commonly referred to as a stripper, which separates a pumping chamber inlet from a pumping chamber discharge. During each revolution of the impeller, the vanes motivate fluid from the inlet to the discharge while interacting with the surrounding pumping chamber to boost the pressure of the fluid at the discharge. The stripper isolates the discharge from the inlet except for individual volumes or slugs of high pressure fuel trapped between the vanes as they traverse the stripper and any blow-by or leakage across the stripper through the running clearance between the impeller and the housing. Under high ambient temperature conditions or high gasoline fuel temperature in automobile fuel pump applications, high pressure gasoline trapped between the vanes and/or leaking across the stripper may flash to vapor near the pumping chamber inlet and create a jet stream cavitation effect disturbing the flow characteristics at the inlet. A regenerative pump according to this invention includes a stripper which relieves the pressure of the trapped gasoline to minimize the jet stream cavitation effect.